Antihunting device.



N0."745,3Z7. PATENTED DEC. 1, 1908.

A. GHUROHWARD. ANTIHUNTING DEVICE.

APPLICATION FILED JUNE 19 1902.

N0 MODEL.

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iatented December 1, 1903 UNITED STATES PATENT OFFICE.

ALEXANDER CHURCHWARD, OF NEI/V YORK, N. Y., ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEIV YORK.

ANTIHUNTING DEVICE.

SPECIFICATION forming part of Letters Patent No. 745,327, dated December1, 1903.

Application filed June 19,1902. Serial No. 112,317. (No model.)

To aZZ whom it may concern:

Be it known that 1, ALEXANDER CHURCH- WARD, a citizen of the UnitedStates, residing at New York, in the county of New York,

State of New York, have invented certain new and usefulImpi-ovements inAntih untin g Devices, of which the following is a specification.

My present invention relates to certain im- [0 provements in antihuntingdevices for use in connection with synchronous motors, rotaryconverters, or .in any other relation where such a device is desirable,and comprises certain novel features, which I have pointed out IS withparticularity in the appended claims.

For a detailed description of my invention reference is to be had to thefollowing specification, taken in connection with the accompanyingdrawings, in which- Figure 1 represents one embodiment of my invention,and Fig. 2 a modification.

In Fig. 1 the shaft 1 is either driven by or forms a continuation of theshaft of the machine with which the antihunting device is to be used.Mounted on this shaft is a fiy-wheel 2, which against the opposition ofa frictional resistance is permitted to move relatively to the shaft.This frictional resistance, attendant upon relative motion between theshaft 0 and fly-wheel, is the factor which clamps out the huntingtendency of the shaft 1. To secure this frictional resistance to motionof the fly-wheel relatively to the shaft, I mount the wheel so that itshub 3 is yieldingly pressed between friction-disks 4 and. 5. Thefrictiondisk 4, which may be of wood, fiber, or the like, is heldbetween the hub 3 and a flange 6, keyed or otherwise fixed to theshaft 1. The disk 5 is pressed against the hub of the flywheel bysprings 7 and 8, placed between the disk 5 and another flange 9, keyedor otl1erwise fixedly secured to the shaft 1. The disk 5 is splined uponthe shaft 1, so as to be capable of a slight longitudinal motionthereon,

but incapable of rotation about the shaft.

Located within a recess in the hub of the fiy-wheel is amagnetizing-coil 10, which is supplied with current fromcollector-rings, (indicated at 11,) upon which bear brushes to whichcurrent is conveyed by means of leads 12.

The friction between the fly-wheel 2 and the parts between which it isyieldingly clamped is sufiicient under ordinary conditions to preventhunting of the machine to which the de- 5 5 vice is connected when themachine is running normally. \Vhen starting up the machine from a stateof rest, however, this friction is insuflicient to bring the fiy-wheelup to speed as quickly as the driving-machine comes up to speed. Underordinary circumstances the fly-whecl requires a considerable time beforeit reaches a speed of rotation synchronous with the driving-machine,during which interval the machine is apt to hunt or pump to a veryinconvenient extent. By exciting the coil 10 with current the disk 5,which is of magneticmateriakisurged strongly against the hub of thefly-wheel by magnetic attraction and constitutes a stiffly yielding, ifnot rigid, connection between the fiy-wheel and the shaft upon which itis mounted. The fly-wheel is thus brought up to speed as quickly as theshaft which drives it, thereby preventing the initial pumping of thedriv- 7 5 ing-machine. It will be evident that by adjusting the amountof current in the exciting solenoid the friction between the flywheeland the shaft maybe adjusted accordingly, and this may be readilyperformed while the device is in normal operation in case adjustment forany reason is then desirable.

In Fig. 2 a somewhat different arrangement is shown. As in Fig. 1, thefly-wheel 2 is mounted on a shaft 1 with one side of its hub 3spring-pressed against a friction disk or plate 4 of suitable material,as wood or fiber, interposed between the hub and the flange 6. On theopposite side of the hub 3 isa disk 13, o loosely mounted on the shaft 1and provided with lugs 14, registering with openings in the hub, asindicated. In these openings are mounted springs 15, which bear againstthe plugs which close the openings. The disk or 5 plate 13, carryingthese lugs, is limited in its motion away from the hub of the fly-wheelby engagement with a disk or sleeve 16, keyed or otherwise fixedlysecured upon the shaft 1. Surrounding the shaft and located adjacent weto the disks 16 is a magnetizing-coil 17, to which current may besupplied from a suit able source by means of collector-rings andbrushes, (indicated at 18,) Asoinewhat cupshapedarmature 19 is splinedupon the shaft 1 and surrounds the magnetizingcoil, as indicated. Uponthis coil being energized this armature is urged toward the flange 16.This operation causes the cylindrical edge 20 of a sleeve-like portionof the armature which projects over and surrounds the disk 16 to pressagainst the movable spring-pressed disk 13. The degree of excitation ofthe magnetizingcoil 17 determines the degree of additional pressure thusexerted upon the hub of the flywheel. By sufficiently exciting the coilthe fly-wheel may be practically locked with reference to the shaft byfrictional pressure, thereby permitting it to be brought up to speedsynchronously with the driving-shaft, after which by decreasing orentirely dispensing with the excitation of the exciting-coil theapparatus may be continued in normal operation.

lVhat I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. An antihunting device for synchronous dynamo-electric machines, orthe like, consisting of a device possessing inertia, an energy-consuming slipping connection between the dynamo-electric machine or the likeand said inertia device, whereby the inertia device is normally driven,and means for substantially locking said connection during starting.

2. The combination of a shaft, a fly-wheel mounted on said shaft andrelatively movable with respect thereto, a spring-controlled frictionalconnection between said shaft and said flywheel, and means adjustablewhile the shaft is in rotation for varying the frictional resistancebetween the shaft and the flywheel.

3. The combination of a shaft, a fly-wheel mounted thereon, means forproducing a frictional resistance to rotation between said flywheel andsaid shaft, and magnetic means for adjusting the frictional resistanceduring rotation of the shaft.

4-. The combination of a shaft, a fly-wheel mounted thereon, mechanicalmeans for pro ducing a frictional resistance to rotation between saidfly-wheel and said shaft, and magnetic means for adjusting thefrictional resistance during rotation of the shaft.

5. The combination of a shaft, a fly-wheel. thereon, friction disks orplates arranged adjacent to the hub of said fly-whee], springs forpressing the friction-plates against the hub of said fly-Wheel, andmeans for locking the friction-plates against said hub or unlocking atwill.

In witness whereof I have hereunto set my hand this 18th day of June,1902.

ALEXANDER ClIUROIllVAltl). lVitnesses:

BENJAMIN B. HULL,

HELEN ORFORD.

